Threaded locking device



Nov. 28, 1944. R. w. LUCE THREADED LOCKING DEVICE Filed Jul 17, 1941 ifivENToR.

WWW

A] TU/QNEY Y 1 UNITED STATE the two threaded portions.

Patented Nov. 28, 1944 THREADED LocmNGnavrce Richard Luce, Southport, Conn.

Application July 17, 1941, Serial 402,726

zClllml. (01.15141) I The invention herein disclosed relates to a threaded locking device-ofthe type in which the locking effect is attained by settingup and maintraining a frictional contact between the surfaces of the engaging threads of two threaded elements.

In United States Letters Patent No. 2,196,637, issued April 9, 1940, there is disclosed and de scribed a threaded locking device of this .kind. The particular device illustrated in that patent isa lock-nut that includes a'body portion having the load-carrying thread therein, another threaded portion spaced from and axially aligned with the body portion and an intermediate resilient portion uniting the two threaded portions. The resilient portion is in the form of asectio'n' of a bellows and it isarranged to partake of a bending action upon relative axial movement of tlons are normally maintained with the threads 1 thereof out of phase. The necessary relative v of another nut blank;

, Fig. 2 which. isan elevation, partly in section, of a nut made-from the blank of Fig. l; t r Fig. 3 which is an elevation, partlyin section,

Fig. 4 which is an elevation; partly in section, of a nut made from the blanklof Fig; 3; and

Fig. 5 which is anelevation, partly in, section, of nut made from a blank of a modified-form like that of ig.3. The blank and, lock,

greater than the bore diameter of the body and The threaded poraxial movement of the threaded portions required to bring the threads thereof'into engaging relation with the thread of a bolt entered therein expands the resilient portion which exerts a force that maintains the threads of the nut 'and the bolt in frictional contact. The resilient portion of such lock-nuts is formed by an internal recessing and external form-cutting operation, This internal re cessing operation-on nuts of the smaller size requires rather delicate tools and in consequence, a slower production rate in the production of the smaller sized nuts, particularly when the nuts are made of tough alloy steel.

An object of the present invention isto provide a threaded locking device of this kind that requires no internal recessing operation. Another object of the invention is to provide such a threaded locking device that is readily produced, even in the smaller sizes, in large quantities at comparatively high rates of production. A further object of the invention is to provide a threaded locking device of this kind that,even in the smaller sizes, may be produced on automatic machinery and comparatively inexpensively.

The foregoing objects and certain advantages that will hereinafter appear are realized in accordance with the invention in the threaded looking devices, constituting certain specific examples of embodiments of the invention, that are illustrated in the drawing and described in detail below. l

The drawing includes: J

the cylinder is axiallysaligned with the body portion; This cylinder in part, formsthe resilient portion of. the finished nut, as hereinafter de- SCribed an'd is oi such wall thickness as toprovide the desired resiliency in accordance with thed particular metal used. In the'blank illustrated the wall ,thicknessof the cylindrical extension is 'slightlylessthan that required totake and maintain a thread. c I

The ,end portion of the cylinder 2 is inturned,

' that is the cylinder is reversely bent, inwardly of a nut blank;

between its ends, to form an inturned extension 3 of the sameinternal diameter as the bore of the body. the metal of the inturned extension is crowded,

that is to say, the same volume of metal is crowded into a circle of lesser diameter. The result is that the inturned extension has a wall section substantially thicker than either the curved connecting portion 4 or the adjacent portion 5 of the cylinder. This inturned extension 3 thus has a wall thickness that is sufilcient to take and maintain a thread.

The blank so formed is tapped, the tap being run through the body of the nut and the inturned extension 3 sothat threads 6 and I of the same pitch are formed in the body and the inturned extension respectively. After the nut is thus tapped, thenut is compressed axially to take a set such that the thread of the inturned extension is positioned slightly out of phase with the thread of the body portion, just slightly more ut illustratedlnFigs. 1

and-'2 is made from hexagonal bar stock. "From, such stock, a. nut blank, as shown in Fig, 1 is me chined. This blank includes a nutbody I with In forming the inturned extension,

service and tending to loosen the nut on the bolt.

The nut blank andnut illustrated in Fi 4 In Fig. 5, there is disclosed. a nut that is likewise made from a blank such as that illustrated in Fig. 3-. The nut includes a body portion I4 is substantially the same as that illustrated in a Fig. 1, but differs therefrom in the cylindrical extension. The nut blank (Fig. 4). includes a nut body 8, bored -longitudinal ly: as at 9, and a cylinder Ill extending from one end of the body. The wall of this cylinder 10 is tapered externally and the wall section is thicker adjacent the nut body than at the end.v The wall thickness of thiscylinder is suflicient to take and maintain a thread.

The portion I is rolled over inwardly to form an mtumed extension I I, of the same internal diameter as the bore '9 of the nut body, axially aligned with the'nut body. When this operation is performed,' the wall thickness of the ini turned extension is sufficient to take and main-.- taln a thread. The .wall t ickness. of the cy1in-- der and thecurved connecting portion. l:2 are reduced in thickness to provide the desired reand an extension I5; reverselybent inwardly, to

form an inturned extension Hi. The end of the blank, from which this'nut is made. that is, the external surface of the reverse bend is ground. reducing the thickness of the wallat this section by the removal of metal between the broken line I! and the adjacent solid line. This constitutes an efficient way of securing the thickness suitable. for "the desired resiliency. The nut blank is then tapped and: compressed to put the thread of the inturned extension lG out of phase with the thread, of the body.- The nut of Fig. 5

may also be made in the same way from a blank such as that of Fig.1. 'In such a case the wall of the extension on the blank would be substantially'thicker. L

From the-foregoing descriptions of the embodiments; of the invention illustrated in the drawing, it will be seen that by this invention.

there is provided a lock-nut with a smooth, un-

broken surface. Also the overall height or length of the nut is not much greater than an ordinary nut.-

It will be obvious that various changes may be made by those skilled in the art in the details of the embodiments of the invention, illustrated in the drawing and described in detail.

' abovewithin the principle and scope of the insiliency. This reduction may be effected with a form cutting'tool which removes thernetal from the external side as between thebroken line l3 and the solid line (Fig. 4). In this way the thickness for the desired resiliency is attained. By making the nut in this way the relative wall thickness of the intumed extension I I, the cylinder [0 and the connecting section 12 may be more accurately controlled.

Next the. nut .is tapped. The tap is run through the body and the inturned extension so that each has the same thread. After the nut is. tapped, it is compressed axially to take a set with. the thread of the intu-rned extension. out

of phase with the thread of the nut body. The out of phase relation is slightly more than required to take up the commercial thread tolerances.

vention as expressed. in the appended claims.

Iclaim:

1. A lock-nut for effecting a frictional engagement between the threads thereof and the thread of a bolt entered therein comprising an internally tapped body having the load carrying threads therein; an unbroken cylindrical portion at one end of the body portion of larger internal diameter than th body portion and in- Y eluding a tapped extension inturned through substantially one hundred and eighty degrees of greater wall thickness than the cylindrical.

portion and positioned with the thread thereof out of phase with and toward the thread of the body portion.

2. A'lock-nut according to claim ized by the fact that the wall section at the' reverse bend is reduced in thickness.

RICHARD W. LUCE.

1 character- 

